There is a continual need for new food preservatives bearing new and useful properties. Further, there is growing interest in replacing traditional "chemical" food preservatives with effective "natural" preservatives, especially those which are specific for pathogenic microorganisms and do not harm beneficial food-producing strains. In this regard, considerable research has been conducted on bacterial peptides known as bacteriocins which are often heat stable and have antimicrobial activity. Two such bacteriocins which are commercially produced for use as food preservatives are nisin and pediocin PA-1. Nisin has been given the status of Generally Regarded as Safe for human consumption (GRAS) by the United States FDA. Nisin and pediocin PA-1 however, have broad spectrum activity, affecting not only pathogenic, but also beneficial (in the food system) microorganisms.